Burglar-alarm.



J. B. LILJBBLAD.

BURGLAR ALARM.

APPLICATION FILED 00T. 22. 1909.

Patented Mar. 4, 1913.

2 SHEETS-SHEET 1.

Mme/5,5 21S' J. E. LILJEBLAD.

BURGLAR ALARM.

APPLICATION FILED 00T. 22, 1909.

Patented Mar. 4, 1913.

2 SHEETS-SHEET 2.

lil l! i JoIIN EMIL LILQIEBLAD, oF CHICAGO, ILLINOIS.

,Bouman-ALARM.

specification Letters raient.

Application ined oqtber 22', 1909. 'serial No. 524,036.

To all whom zt may concern.'-

Be it known that I, JOHN EMIL LILJE- BLAD, a citizen of the UnitedStatesfand resident of Chicago, in the county of Cook fand State ofIllinois, have invented a certain new anduseful Improvementin`Burglar-Alarms, of which the f ollowin is a. description, referencebeing had to t e accompanying drawings, whlch form a part ofmyspecliication.

My invention relates to an improvement in burglar alarms of the typewherein laline or Wire is secured across or adjacent to places ofingress -to a building or room; the free end'of said line4 or wirebeing. heldin place inany convenient manner, while the other end issecured to mechanism which is held preferably under tension and adaptedto cause an electrical vcircuit to be formed the moment Vthe line orwire is interfered with, thereby sounding the alarm.

In the drawings Figure 1 is a perspective View of the alarm mechanismincased in a small box with the lid shown open and partly broken awayandthe alarm `set'. Fi 2 is a ldetail view inelevation-'of the casing ofthe mechanism whereby the alarm is controlled, looking at the side ofthe casing where the electrodes are brought into contact. Fig. 3 is adetail view in elevation of said mechanism, lookingat the o pen side ofthe casing wherein the operating-mecha nism'is mounted. Fig. 4 is ajlonitudinal sectional view on the line 4- -4 o Fig. 3. Fig. 5 .illustratesmy invention applied to a transom, 'with 'tripping 'mechanism securedonto a door whereby the movement of either the transomy or door will setoff the alarm. Fig. 6 is a side view ofthe tripping mechanism shown inFig. 5 with a por-.t tionv of, the doorLcasing shown in section. Fi 7 isa detail view partially in section an taken on the line 7- -7 of Fig. 6and looking in the direction of the arrows, illustrating the meansemployed whereby the tripping mechanism may be placed into po sition toengage or trip the means vfor releasin the electrical contacts orelectrodes where y the circuit is controlled, and vvthe alarm mechanismactuated. Fig. 8 is'fa detail view of `the combination or 'means shownin Fig. 7, illustrating that portionl whereby the position of thetripping-'mechanism is determined.

To illustrate the rinciple 'of m in v'en- 'sition. In order to tion, Ihave shown t e alarm set in Fig.

5, by 1eading`"tl1e line 1f-which may be either a string orl wire orother suitable device-.-

across thellower part of the transom A with its freejend secured at b.This line a leads tothe alarm-circuit controlling mechanism. the alarmmay forl which, together wit conveniencebe inclosed in a box B. Thealarm comprises the ordinary style of elec-A tric-bell C; the currentbeing supplied by a suitable battery D, which -is wired to' the also ,toplug d by wire 0 ,-see Fig. .1

Patented Mar. 4, 1913;.

and the circuit is completed through switch e when the latter is movedinto contact with plug j, through wire g connected with `con tact-pieceor electrode h, electrode z', through the metallic casing or Wall E andwire-j to the other plug of the bell. As the bell is of a well-knowntypel it will not be. necessary to follow out the manner in which thecurrent passes through the electro-magnet and vibrating member.Contact-piece or electrode h preferably has its free end bifurcated orook-shaped to ,take about the free end of electrode or contact-pointe',as clearly shown in Figs. l and 2. The electrode k,

itvwill be understood, is secured to the box. i

B,' which is made of woodor other non! conducting material, or to awooden block vorv other insulating material wit-hin the box,

contact-point i is pivotally secured at -cfto wall ET' and takes overthe top of gear Zand throu h the curved or eccentric slotn4 in wall andbetween the bifurcated end of contact-piece L, as can clearl be seen inFigs. 3 and 4.` Electrode z' 1s preferably made to bear frictionallyagainst the wall ofslot m in an suitable manner, as for exampleby-maklng electrode in the nature of a spring-arm with the coil or twisttherein as shown in Fi 1 at c, which tends to frictionally hold t efreeend of the electrode against the upper wall of the slot as Vclearlyshown. A v Suitably mounted between the 1 walls E L `casing E as clearlyshown inFig. 1. Y

susv

clock-spring, type, whic` ezxierts its tension on gear o so' as toreturn itto' its normalpoth Sprlngproperly keep in place, providedis c."Secure to gear t, and gear Z are secured, to wind up the Z. and alsoAconnected with pinion p, is the;

drum or spool t on which is wound the string or'wire a, Fig. 5, whosefree endmay be provided with a loop or hook to permit of its'beingreadily drawn out and secured at the desired point. y p

It is apparent from the foregoing that the tension of spring -1 tends,through the medium of gear o which meshes with pinion p mounted on thespindle g on which thespool string or wire a onto spool t, so that themoment the free end of the string or wire a is released or broken away'from its fastening,

the gear Z will be permitted to revolve in a direction that will take:up the unwound portion of the wire or string, It is also apparentthat'- the drawing out of string or wire a will compel 'the spool t andwith itY spindle g and gear Z to revolve in the opposite direction fromthat in which the tension of the spring exerts itself. 'Ihe nature ofslot m is such that when electrode is moved toward the center of theslot, the electrode will be made to take between the teeth of gear?. Itis apparent therefore, that when the` electrode z' is thus set, amovement of gear Z in either direction will also compel electrode z' tomove in the same direction until the electrodereaches the ends of theslot fm, when it will be out of contact with gear Z and as the distancebetween the bifurcated end of electrode h is less than the length ofslot m, the electrodes z' and l1, will be brought into contact with eachother andthecircuit closed.

The alarm is set by drawing out the string or wire a and fastening itacross the path' that will necessarily be'taken orto the window or door,thereby also unwinding spring r and increasing its tension; when thestring has been fastened in place, the electrode i, is moved into thecenter of slot m, bringing it into contact with the teeth of gear Z.evident, that if. the string or wire a is drawn out farther, gear Z willturn and `.move electrode z' toward one end of slot m, and int-0 contactwith one branch of stationary elec` trode h; while the release of stringvor wire a will permit the tension of spring r to exert itself and turngear Z in the op osite direction and force electrode from t e center ofslot m; toward the otherside of slot m and into contact with the otherbranch or bifurcation of electrode h, thus, in either event, closing thecircuit.

' In `order that the4 alarm may be set during absence, and at the sametime permit of lone string or wire answering for both door and transom,I provide aV tripping mechanism as villustrated in Fig. 5, whichconsists of rod F, the lower end of which is formed or provided with arack as shown at u; vwhile the upper end of the rod may be bent to takeover the casing intermediate of It isv the door-top, and the transom, ifthe casing prQirudes to any extent beyond the perpendicujlar planeofdoorand transom. The upper: end of rod'F is preferably provided with thehook-portion u-see Fig. G-which is so formed as to present its pointstoward each other,.leaving only a small distance'between the tips as''clearly shown in Fig. 6. When the alarm is set for the transom anddoor, the string or wire a is passed through the hook or encirclingportion u as shown in Figs. 5 and 6. Secured onto .the outside of thedoor is knob G, whose shank takes through the door and has its inner endprovided with a pinion o which meshes with the rack u on rod F. Theinner end of the 4shank of knob G may also be provided with a similarknob so that rod F can be operated and put into the desired positionfrom the inside.

In order that the posit-ion of the hookportion of the rod with referenceto the string or wire a may be determined, dials H,-see Fig. S-may beemployed, provided with designations or degrees as indicated. Therelation between the dial and knob is such that when a redeterminedpoint-or pointson the knob reaches a selected designation or degree onthe dial, the hook-portion of the rod F will be in such position as topermit of the opening ofthe door, allowing the string or wire to passbetween the points of the hook, thereby leaving the strin undisturbed.

It 1s apparent from the foregoing description, that when aparty'abouttopass out of the door wishes to leave thev alarm set, theknob on the inside is turned until the selected points on knob and dial`register,.

bringing the hook-portion into position to permit it t0 pass the stringa without interfering therewith and then after passing out and closingthe door, the knob G on the outside is turned to throw the designatedpoints out of register, thereby again bringing one ofA the points intothe horizontal plane of the' string or wire a, as shown in Fig. 6.

It is apparent, that if the transom A is opened it'will bend rodF,-which may be light or fieXible-and pull on string or wire a therebyoperating the alarm on the other hand, should the door J be opened, thestring or wire a willv be pulled by hook u as previously described. y.

The lower portion of rod F, together with pinion u may be covered by aplate as shown at K, Figs. 5 and 6. When the mechanism is to be inclosedin a box B as shown in Fig. 1, it is advisable to provide the box withan opening as shown at L, so that the alarm can be distinctly heard; andthis opening may be covered with a screen er wire gauze so as to lhowever of placing all the mechanism in a box as shown, the electricdoor bell may be electrically. connected with the setting mechanismwhich can be located at any convenient place. l l

It is clear the mechanism shown and described may be altered in certaindetails without departing from the spirit of my in vention, and I do notwish to be understood as limiting myself to 'the exact construction 'setforth.

v .It is also apparent that the device may `be used as a -re-alarm-byarranging the hnes, formed of any inflammable or fusible material, abouta building, so that the moment' the spring-controlled mechanism isreleased,

-the alarm will be sounded. u

`side of the slot so as ,toA maintain an ad-v justed position, saidelectrode bein pressed into engagementy with the fsprin con trolledgearing when moved into 1ts.adjusted position, astationary electrodewhose free end extends about the pivoted electrode' and' out of contact'therewith when the piv oted electrode is in its adjusted position,means secured to the extended hub or spool and to be wound thereon, theother end of- `said means being adapted to be secured at some distan-,cefrom the hub or spool, so that when said means is moved the springcontrolled'gearing will rotate and move thefpivoted electrode 'out ofits adjusted. position and into contact with the stationary electrode. v

2. A burglar alarm, comprising a casing provided with a transverselyextending slot in one of its sides, the portion of the slot intermediateof its ends extending into a lower horizontal plane than theends, aspring controlled spool or .drum mounted in said casing and having aserrated or toothed rim, anannunciator arranged in a normally openelectric circuit, a .pivotally mounted resilient electrode the endwhereof extends through said slot and has frictional engagement with theupper side thereof, the 1votally 'mounted electrode being adapt to 'bebrought into engagementwith` the serratedor toothed rim when the outerend of the:` electrode is moved to a point intermediate of the ends ofsaid slot, a stationary electrode havin a bifurcated end extending toopposite sides of the pivoted electrode, and a cord or wire winding onsaid -spool or drum, the one end of said cord or wire being adapted tobe secured4 at a point removed from the alarm and revolvin the spring,so that whenv the cordv o r wire is in- 'fterfeed with the spool will'revolve and movevthe pivotally mounted electrode-into contact with thestationary electrode.

JOI-IN` EMIL LILJEBLAD.

Witnesses: y

GUs'rAr A. AKERLIND, NORMAN A. STREET.

spool or drum against the action o .the

